This application claims the priority of German Patent Document 199 56 825.1, filed Nov. 25, 1999, the disclosure of which is expressly incorporated by reference herein.
The invention relates to a cylinder head for an internal-combustion engine having inlet and outlet valves for the charge cycle control in a combustion space of the cylinder head, which valves are actuated at least one camshaft.
Internal-combustion engines of the Otto construction having a manifold injection or a direct injection have considerable development potentials, among others, with respect to exhaust gas emissions and fuel consumption. This may affect the manufacturers of these internal-combustion engine in that, in the future, they will use both injection systems for different types of internal-combustion enginesxe2x80x94with a manifold injection or a direct injectionxe2x80x94but, for example, with the same number of cylinders.
An internal-combustion engine is known from European Patent Document EP 0 594462 A1 (corresponding to U.S. Pat. No. 5,379,743) which operates by means of a manifold injection. Here, an injection nozzle is provided in an intake pipe which leads to an inlet valve and a combustion space.
From German Patent Document DE 19804 161 A1, an internal-combustion with a direct injection is known which comprises an injection nozzle leading into a combustion space. The combustion space is formed by a profiled piston head and a gable-roof-type ceiling of a cylinder head. The cylinder head is provided with inlet and outlet valves arranged in a V-shape and with a central spark plug extending between the latter.
It is an object of the invention to design a cylinder head such that, while constructional realities are taken into account, it will be suitable for different internal-combustion engines with a manifold injection or a direct injection.
According to the invention, this object is achieved by providing a cylinder head for an internal-combustion engine having inlet and outlet valves for the charge cycle control in a combustion space of the cylinder head, which valves are actuated by at least one camshaft,
wherein a cylinder head system comprising inlet valves and outlet valves has constructional characteristics which are suitable for a first cylinder head variant with a manifold injection as well as for a second cylinder head variant with a direct injection such that at least the constructional characteristics valve angle of the first cylinder head variant and of the second cylinder head variant correspond to one another, the second cylinder head variant being provided with at least one injection nozzle installed from a longitudinal side of the second cylinder head variant, each of the at least one injection nozzle extending at an acute angle with respect to a plane extending between the second cylinder head variant and a cylinder housing when in an assembled in use position.
Additional advantageous features of preferred embodiments of the invention are described below and in the claims.
Principal advantages achieved by the invention are the fact that, because of concurring construction characteristics, the first cylinder head variant and the second cylinder head variant are produced by identical manufacturing and mounting devices, which has a cost reducing effect. Thus, it is possible that one and the same manufacturer of internal-combustion engines presents a basic design of an internal-combustion engine, for example, with a crankcase having six cylinders. On the above-mentioned crankcase, the first cylinder head variant or the second cylinder head variant is mounted according to the type of injectionxe2x80x94manifold injection or direct injection. Furthermore, in the case of both cylinder head variants, identical and/or proven design principles for the outlet and inlet ducts, the cooling water ducts, and the valve angles can be provided. It is also contemplated to use for this cylinder head variant identical parts such as bucket tappets, valve guides or the like. Finally, the second cylinder head variant can be constructed in a simple manner if it is tilted with respect to the first cylinder head variant over a first longitudinal side by a defined amount and the injection valves are mounted on the second longitudinal side.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.